1. Field of the Invention
This invention relates to an electrically rewritable and non-volatile semiconductor memory device, especially relates to an improvement of the write mode.
2. Description of the Related Art
A NAND-type flash memory is well known as one of EEPROMs. In the NAND-type flash memory, data read and write are performed by a page. One page is, for example, formed of a main column area of 4 kByte and a redundant column area of 64 Byte, which are summed up to 4160 Byte. User data are usually input and output Byte by Byte.
In the test of the NAND-type flash memory before shipping, it will be tested whether a predetermined user data is normally written or not (for example, refer to JP-2007-250187A). If test-use write data is supplied to IO pins by one Byte like in a normal write mode, it takes 124.8 μs to load one page test data of 4160 Byte on the assumption that the write cycle is 30 ns.
As described above, it takes a long time to load write test data, and there is a fear that the test time increases in accordance with the page length increase in future.